Output control apparatus for stirling engines

A Stirling engine output control apparatus comprising:

• a working gas compressor;
• a maximum cycle pressure line connecting a working space to said working gas compressor via a first check valve;
• a pressure reducing valve provided in said maximum cycle pressure line;
• a minimum cycle pressure line connecting said working space to said working gas compressor via a second check valve;
• a pressure boost valve provided in said minimum cycle pressure line;
• an operating lever pivotable about a movable pivot point for controlling opening and closing of said pressure reducing valve and said pressure boost valve;
• a motor for moving said movable pivot point;
• electronic control means for driving said motor;
• sensing means for supplying said electronic control means with signals indicative of engine rotating speed, displacement of said operating lever and working gas pressure;
• and
• an unload valve provided in a line shorting intake and discharge sides of said compressor;
• said electronic control means having means for moving said movable pivot point via said motor so as to control working gas pressure in accordance with a reference target pressure decided by engine rotating speed and amount of operating lever displacement in neutral and parking ranges, and in accordance with a practical target pressure obtained by adding a pressure increment to said reference target pressure in a drive range.